The increased terminal mobility offered by cellular telephone networks as well as mobile and WiFi radio data networks has brought about an increased demand for location-based services and applications. Location based services include, for example, fleet management, vehicle tracking, tracking for theft recovery, telemetry, emergency services, location identification, navigation, location based information services and location based advertising. A wide variety of technologies for locating mobile devices have been developed.
Geoanalytic Radio Access Network (RAN) monitoring and optimization systems utilize NEM (Network Equipment Manufacturer) RAN signaling to troubleshoot mobile subscribers' issues and to provide RAN performance KPIs. These systems utilize geolocation techniques such as triangulation to obtain subscriber location awareness (latitude/longitude) and enhance this geolocated data with Radio Frequency (RF) quality. This subscriber location awareness information can then assess if the subscriber was in good or bad RF conditions during a voice or data session. The accuracy of the geolocated data depends upon many factors and results better than ⅛ inter cell spacing is difficult to achieve. Additionally, the algorithms utilize ‘morphologies’ of the landscape types (building density, building height, highway, roads, lakes, forests, etc.) in the geolocation calculation.
Typical mobile device location technologies may be classified into external methods and network based methods. One example of an external method is the Global Positioning System (“GPS”). Network based methods (such as triangulation) may be further categorized depending on whether it is the network or the mobile device that performs necessary signal measurements. These signal measurements may involve the transmit power of a base station received by a mobile device, reception time of signals communicated between a base station and a mobile device, the angle of arriving signals or round trip delay measurements of signals communicated between a serving base station and a mobile device, or combinations thereof. One way to improve the accuracy of the stored geolocated data is to “calibrate” critical areas with drive test results where external reliable geolocation sources, such as GPS, are used to achieve about 5 meter accuracy.
However, drive testing is not advantageous in terms of cost and is seldom performed. Nevertheless, for many current and future location based applications, accuracy of the calculated position information should be improved.